Additionally, our construction achieves several desirable features:
• Our construction for reusable garbled circuits for NC 1 achieves the optimal “full” simulation based security.
• When generalised to handle Q queries for any fixed polynomial Q, our ciphertext size grows additively with Q^2 . Such query dependence on ciphertext size has only been achieved in a weaker security game otherwise [Agr17].
• The ciphertext of our scheme can be divided into a succinct data dependent component and a non-succinct data independent component. This makes it well suited for optimization in an online-offline model that allows a majority of the computation to be performed in an offline phase, before the data becomes available.
Security of our scheme may be based on the Learning With Errors assumption (LWE) or its ring variant (Ring-LWE). To achieve our result, we provide new public key and ciphertext evaluation algorithms in the context of functional encryption. These algorithms are general, and may find application elsewhere.
Category / Keywords: Functional Encryption, Learning with Errors, Online-Offline, Fully Homomorphic Encryption Original Publication (with minor differences): IACR-TCC-2017 Date: received 8 Apr 2016, last revised 14 Sep 2017 Contact author: shweta a at gmail com Available format(s): PDF | BibTeX Citation Version: 20170914:082037 (All versions of this report) Short URL: ia.cr/2016/361